Moore's lifelong love of astronomy began at an early age, and at the age of 11 he joined the British Astronomical Association and at 14 he was invited to run a small observatory. He was particularly fascinated by the moon, performing the first detailed study of Mare Orientale with astronomer H.P. Wilkins in 1946 and publishing his first book, Guide to the Moon, in 1952.

He was first invited on television to debate the existence of UFOs after a rash of supposed sightings in the 1950s. After arguing against the existence of flying saucers, Moore was invited to host a regular astronomy program on the BBC, a program that became The Sky at Night. Moore holds the record as the longest-serving presenter on any television program; even when his arthritis hampered his ability to travel to the BBC studio he continued to host the program from his own home. He missed only one episode of his monthly show while suffering from a dangerous bout of Salmonellosis in July 2004. He also served as the GamesMaster on the video game-themed show of the same name.

Many folks who have pursued space-related careers—as well as armchair lovers of science—credit their fascination with the cosmos to Moore's irrepressibly enthusiastic approach to space education. For decades, he helped viewers see the vastness of space while making that vastness a little more familiar with a friendly smile and a tone that conveyed his own amazement at the wonders of the universe. He will be missed.